Adhesive coating material

ABSTRACT

Disclosed is an adhesive coating material for a hard tissue, which comprises (1) a polymer having an acid value of 30 to 700 and including a hydrophobic group and two carboxyl (--COOH) groups or one carboxylic anhydride ##STR1## group bonded to the polymer, said carboxyl groups or carboxylic anhydride group being bonded to adjacent carbon atoms, and (2) an organic titanate compound.

BACKGROUND OF THE INVENTION

(1) Field of the Invention:

The present invention relates to an adhesive coating material for a hardtissue, which comprises a specific polymer and a specific compound incombination. More particularly, the present invention relates to anadhesive coating material for a hard tissue, which comprises (1) apolymer having an acid value of 30 to 700 and including in recurringunits a hydrophobic group and two carboxyl (--COOH) groups or onecarboxylic anhydride ##STR2## group bonded to the polymer, said carboxylgroups or carboxylic anhydride group being bonded to adjacent carbonatoms, and (2) an organic titanate compound.

(2) Description of the Prior Art:

Various compounds are known as adhesives having particular applicabilityin specific fields. Among these adhesives, especially severerequirements are imposed on dental adhesives used for bonding to hardtissues under humid condition. Since a dental adhesive is used in theoral cavity, a high adhesion strength in the humid condition isrequired. Furthermore, this dental adhesive should have an adhesiveforce to both of hard tissue and a dental resinous restorative materialcomprising a polymerizable monomer and at least one member selected frominorganic, organic and inorganic/organic composite fillers.

As dental adhesives, an ionomer cement comprising an aqueous solution ofpolyacrylic acid and inorganic oxide, and a cold-setting adhesivecomprising a polymerizable monomer are widely used.

The Ionomer cement has an adhesive force to the hard tissue, but noadhesive force to a dental resinous restorative material. And theIonomer cement is readily separated from the bonded portion since itswater resistance is low.

The cold-setting adhesive comprising a polymerizable monomer hardlyadheres to the hard tissue without pretreatment. Accordingly, it isnecessary that the hard tissue should be treated with a highlyconcentrated aqueous solution of phosphoric acid to prepare a mechanicalretentive surface. This method, however, is defective in that evenhealthy hard tissue is damaged since phosphoric acid is used at a highconcentration.

Special properties are required for adhesives according to applicationfields thereof, and a certain adhesive usable in a certain field canseldom be used industrially in other fields. Accordingly, specialadhesives are used in respective application fields, and also in thefield of the dental treatment, development of an adhesive satisfying theforegoing requirements is eagerly desired.

SUMMARY OF THE INVENTION

Under the above-mentioned background, we carried out research with aview to developing a satisfactory adhesive coating material for a hardtissue, and we have now completed the present invention.

It is therefore a primary object of the present invention to provide anadhesive for a hard tissue, which can be bonded to a hard tissuedirectly without a pretreatment with an aqueous solution of phosphoricacid.

Another object of the present invention is to provide an adhesive whichcan be bonded with a sufficient adhesive force to a tooth and a dentalresinous restorative material even in the oral cavity in the humidcondition and which has a high water resistance.

Other objects and advantages will become apparent from the descriptiongiven hereinafter.

In accordance with a fundamental aspect of the present invention, thereis provided an adhesive coating material for a hard tissue, whichcomprises (1) a polymer having an acid value of 30 to 700 and includinga hydrophobic group and two carboxyl (--COOH) groups or one carboxylicanhydride ##STR3## group bonded to the polymer, said carboxyl groups orcarboxylic anhydride group being bonded to adjacent carbon atoms, and(2) an organic titanate compound.

DETAILED DESCRIPTION OF THE INVENTION

One main component of the adhesive coating material of the presentinvention is a polymer including a hydrophobic group and two carboxylgroups or one carboxylic anhydride group bonded to the polymer, saidcarboxyl groups or carboxylic anhydride group being bonded to adjacentcarbon atoms. The reason why the hydrophobic group is introduced intothe polymer used in the present invention is that a sufficient waterresistance is given to the adhesive coating material, a goodcompatibility or affinity with a resin to be bonded, for example, adental resinous restorative material, is imparted to the adhesivecoating material and a sufficient adhesion strength is obtained even inthe humid condition. Furthermore, in order to attain a sufficientadhesive strength to the hard tissue even in the humid condition, it isnecessary that the two carboxyl groups or one carboxylic anhydride groupshould be bonded to adjacent carbon atoms in the polymer to be used inthe present invention. Since the two carboxyl groups or one carboxylicanhydride group forms a bridge of a high strength with the organictitanate compound used as the other component of the present invention,an especially high water resistance is given to the adhesive coatingmaterial of the present invention. Accordingly, the adhesive coatingmaterial of the present invention acts effectively as an adhesivebetween a hard tissue and a dental resinous restorative material such asa composite resin, especially in the humid condition. In view of theforegoing description it is most preferred that the adhesive coatingmaterial of the present invention should comprise (1) a polymerincluding a hydrophobic group and two carboxyl groups or one carboxylicanhydride group bonded to adjacent carbon atoms, and (2) an organictitanate compound.

It also is important that the polymer that is used in the presentinvention should have an acid value of 30 to 700, especially 40 to 600.In the instant specification, the acid value is defined as the number ofmg of KOH necessary for neutralizing 1 g of the polymer. This acid valueindicates the concentration of the carboxyl group or carboxylicanhydride group in the polymer. If the acid value is smaller than 30,the adhesiveness to the hard tissue is reduced and the number ofcrosslinking points to the organic titanate compound is reduced, withthe result that the toughness of the resulting coating is degraded. Ifthe acid value is larger than 700, the coating formed from the polymeris excessively hydrophilic, and the water resistance is reduced. Apolymer having an acid value within the above-mentioned range isespecially suitable as a dental adhesive coating material.

The kind of the hydrophobic group bonded to the polymer is notparticularly critical in the present invention, and any of knownhydrophobic groups may be used. As preferred examples of the hydrophobicgroup, there can be mentioned (1) aryl groups such as phenyl andnaphthyl groups, (2) alkyl groups such as methyl, ethyl, propyl andbutyl groups, (3) alkoxy groups such as ethoxy, propoxy and butoxygroups, and (4) acyloxy groups such as an acetyloxy group. Thesehydrophobic groups (1) through (4) may be substituted with othersubstituents, such as halogen atoms, e.g., chlorine, bromine, iodine andfluorine, and alkyl, alkoxy and phenoxy groups.

In many cases, the hydrophobic group is ordinarily introduced into thepolymer from a starting material used for the production of the polymer,as described hereinafter. The kind of the hydrophobic group-givingstarting material is not particularly critical, and a known vinylmonomer is preferably used. More specifically, there are preferably usedstyrene, halogenostyrene, methylstyrene, halogenomethylstyrene andvinylnaphthalene as the monomer having the hydrophobic group (1),propylene and isobutene as the monomer having the hydrophobic group (2),ethylvinyl ether and n-butyl ether as the monomer having the hydrophobicgroup (3) and vinyl acetate as the monomer having the hydrophobic group(4).

A monomer for introduction of the hydrophobic group, which is especiallypreferred in the present invention, is represented by the followinggeneral formula: ##STR4## wherein R¹ stands for a hydrogen atom or analkyl group, and R² stands for an aryl group, an alkyl group, an alkoxygroup or an acyloxy group.

In the polymer used in the present invention, it is sufficient if thecarboxyl groups or carboxylic anhydride group is finally bonded toadjacent carbon atoms, irrespectively of the preparation process.Ordinarily, a polymer having two carboxyl groups or one carboxylicanhydride group bonded thereto is preferably prepared by performinghomopolymerization or copolymerization by using as the starting materiala vinyl compound having two carboxyl groups or one carboxylic anhydridegroup bonded to adjacent carbon atoms, such as maleic acid, fumaricacid, itaconic acid, maleic anhydride or itaconic anhydride.Furthermore, there is preferably adopted a process in which a vinylmonomer having a carboxylic acid ester group or carboxylic anhydridegroup bonded to adjacent carbon atoms, such as maleic anhydride, maleicacid monoester, maleic acid diester, fumaric acid monoester or fumaricacid diester is used as one polymerizable component and copolymerizedwith other copolymerizable vinyl monomer, and the carboxylic anhydridegroup or carboxylic acid ester group of the formed copolymer ishydrolyzed to convert all or a part of the carboxylic anhydride group orcarboxylic acid ester group to a carboxyl group.

The kind of the polymer that is used in the present invention is notparticularly critical, so far as it includes a hydrophobic group asmentioned above and two carboxyl groups or one carboxylic anhydridegroup and the two hydroxyl groups or one carboxylic anhydride group isbonded to adjacent carbon atoms. In view of the availability and thehandling easiness, it is industrially preferred that a polymer having anaverage molecular weight of 1,000 to 100,000, especially 2,000 to50,000, be used. The process for the preparation of this polymer is notparticularly critical. From the industrial viewpoint, however, there ispreferably adopted a process in which a vinyl monomer having ahydrophobic group, such as mentioned above, is copolymerized with avinyl monomer having a carboxyl group, a carboxylic acid ester group ora carboxylic anhydride group bonded to adjacent carbon atoms and, ifnecessary, the obtained polymer is then hydrolyzed.

A preferred polymer comprises (A) at least one kind of recurring unitsrepresented by the following formula: ##STR5## wherein R¹ stands for ahydrogen atom or an alkyl group, and R² stands for an aryl group, analkyl group, an alkoxy group, an acyloxy group or an alkoxycarbonylgroup, and (B) at least one kind of monomeric units represented by thefollowing formula: ##STR6## wherein R³ stands for a hydrogen atom or acarboxymethyl group, n and m are numbers of zero or 1, with the provisothat when n is zero, m is 1 and R³ is a hydrogen atom and when n is 1, mis zero and R³ is a carboxymethyl group, and the two carboxyl groups mayform a carboxylic acid anhydride group.

The above-mentioned copolymerization is not particularly critical.Ordinarily, however, there is preferably adopted a polymerizationprocess in which a polymerization initiator described below is used.More specifically, there is preferably adopted a radical polymerizationprocess using an organic peroxide such as benzoyl peroxide or lauroylperoxide, an azo compound such as azobisisobutyronitrile, an organicmetal compound such as tributyl boron or a redox type initiator.

In the above-mentioned polymer, it is preferred that the hydrophobicgroup be contained in an amount of 0.7 to 9.0 moles per mole of the twocarboxylic groups or the one carboxylic anhydride group. If the contentof the hydrophobic group is higher than 9.0 moles, no satisfactoryadhesive force to a hard tissue can be obtained. The reason is notsufficiently elucidated, but it is presumed that since the hydrophobiccharacteristics of the copolymer are increased, the affinity with thehard tissue will be reduced. If the hydrophobic group is contained inthe polymer in an amount smaller than 0.7 mole, there is not a suitableprocess for imparting a carboxyl group or carboxylic anhydride group tothis copolymer, and therefore, the production of this copolymer isdifficult and the water resistance of an adhesive comprising thispolymer is not sufficient. As is apparent from the foregoingdescription, the content of the hydrophobic group in the polymer used inthe present invention is very important.

The above-mentioned process in which the carboxylic acid ester group orcarboxylic anhydride group is hydrolyzed is not particularly critical.Ordinarily, there is preferably adopted a process in which a copolymercomprising maleic anhydride, maleic acid diester, fumaric acid diesteror itaconic acid diester is dissolved in an organic solvent, water and asmall amount of an alkaline or acid component as a hydrolysis promotorare added to the solvent and the reaction is carried out at roomtemperature or under heating.

An organic titanate compound is used as still another component of theadhesive coating material of the present invention. The kind of theorganic titanate compound is not particularly critical, and any of knownorganic titanate compounds can be used. For example, there can bementioned tetra-isopropyl titanate, tetra-n-butyl titanate,tetrakis(2-ethylhexyl) titanate, tetrastearyl titanate,di-iso-propoxy-bis(acetylacetone) titanate,di-n-butoxybis(triethanolamine) titanate, dihydroxy-bis(lactic acid)titanate, tetraoctylene glycol titanate, tri-n-butoxymonostearyltitanate, isopropyltri-iso-stearoyl titanate,isopropyltridencybenzene-sulfonyl titanate, isopropyl-tris(dioctylpyrophosphate) titanate, tetra-iso-propyl-bis(dioctyl phosphite)titanate, tetraoctyl-bis(ditridecyl phosphite) titanate,tetra-(2,2-diallyloxymethyl-1-butyl)-bis-(ditridecyl phosphite)titanate, bis(dioctyl pyrophosphate)oxyacetate titanate and bis(dioctylpyrophosphate)ethylene titanate. These organic titanate compounds may beused singly or in the form of mixtures of two or more of them. Moreover,polymers of these titanates may be used.

In the present invention, an organic titanate represented by thefollowing formula: ##STR7## wherein R⁴ stands for an alkyl group and pis a number of from 0 to 20, especially a tetraalkyl titanate, ispreferably used as the organic titanate compound.

The adhesive coating material of the present invention comprises theabove-mentioned polymer, and an organic titanate compound as theconstituent components. The mixing ratio of these main components is notparticularly critical, so far as the intended adhesive effect isattained. It is preferred that the organic titanate compound be used inan amount of 0.02 to 2 moles per mole of the unit having the bondedcarboxyl group or carboxylic anhydride group in the polymer.

In the case where the organic titanate compound is used as one componentof the adhesive coating material of the present invention, in order touse the adhesive coating material in a more stable state, it ispreferred that a stabilizer for the organic titanate compound be used.Especially in the case where a solvent is used when the adhesive coatingmaterial of the present invention is actually applied, it is oftenpreferred that water contained in the solvent be not removed and astabilizer for the organic titanate compound be used. An appropriatestabilizer is selected and used according to the application mode of theadhesive coating material of the present invention. For example, when ano-alkoxybenzoic acid such as o-methoxybenzoic acid, o-ethoxybenzoic acidor o-propoxybenzoic acid, or a β-hydroxycarboxylic acid such ashydroacrylic acid, β-hydroxybutyric acid or β-hydroxyisovaleric acid, isused as the stabilizer, a one-pack type product comprising a solventsolution of the above-mentioned polymer and organic titanate compound inone packing vessel can be provided. When an β-hydroxycarboxylic acidsuch as lactic acid, α-hydroxy-n-butyric acid or mandelic acid, aβ-hydroxyalkyl acrylate or methacrylate such as β-hydroxyethylmethacrylate, β-hydroxypropyl acrylate or glycerin dimethacrylate, acatechol derivative such as catechol, guaiacol or eugenol, a prolinederivative such as proline, 4-methylene-proline or 4-methylproline, or acyclic ester such as β-butyrolactone, γ-butyrolactone or β-caprolactone,is used as the stabilizer for the organic titanate compound, theadhesive coating material of the present invention is applied in theform of a two-pack type product in which a solvent solution of theabove-mentioned polymer and a solvent solution of the organic titanatecompound and the stabilizer are contained in different vessels and boththe solutions are mixed together at the time of application. The kind ofthe solvent to be used for the one-pack type or two-pack type product isnot particularly critical, and an appropriate solvent is selected amongknown solvents. Ordinarily, there are preferably used alcohols such asethyl alcohol and isopropyl alcohol, esters such as ethyl acetate, anddioxane and tetrahydrofuran. The amount added of the stabilizer for theorganic titanate compound differs according to the kind of thestabilizer and it is not sweepingly determined. However, it isordinarily preferred that the stabilizer be used in an amount of 0.1 to4 moles, especially 0.5 to 2 moles, per mole of the organic titanatecompound. The stabilizer may be mixed with the organic titanate compoundin advance or it may be added to the organic titanate compound togetherwith other ingredients.

As is apparent from the foregoing description, the adhesive coatingmaterial of the present invention has a very high adhesiveness to a hardtissue and a synthetic resin, and this adhesiveness is excellent even inthe humid condition. Accordingly, the adhesive coating material of thepresent invention can be used especially advantageously as a dentalrestorative material. By the term "dental restorative material" is meanta material which is used for remedy and restoration of a tooth and iscoated on the surface of the tooth or the surface of the cavity formedon the tooth, and this is the most important use for the adhesivecoating material of the present invention. As the dental restorativematerial, there can be mentioned, for example, a tooth adhesive, aprotective lining material for the dental pulp and a border sealer for atooth and a restorative material.

An embodiment where the adhesive coating material of the presentinvention is used as a dental restorative material will now bedescribed.

In the conventional method of remedy and restoration of teeth, when afiller such as a composite restorative resin is filled in a cavity of atooth, an adhesive is used for bonding the restorative material to thehard tissue. However, since a conventional adhesive has no substantialadhesiveness to the hard tissue, it is necessary to treat the hardtissue in advance with an aqueous solution of phosphoric acid to preparea mechanical retentive surface. This method, however, is defective inthat since an aqueous solution of phosphoric acid having a highconcentration is used, even the healthy dentin is damaged. Especiallywhen the dentin is etched, attainment of any substantial adhesive forcecannot be expected and it is anticipated that even the pulp will beinfluenced by the aqueous solution of phosphoric acid introduced throughductules of the dentin. Furthermore, in the method described before,since a residual monomer is inevitably left, there is a risk of damageof the pulp by this monomer.

In contrast, when the adhesive coating material of the present inventionis used, since the pretreatment with an aqueous solution of phosphoricacid is not necessary and the adhesive coating material can directly bebonded to the dentin, there is no risk of damage of the pulp by aresidual monomer.

A lining material of the calcium hydroxide type or a cement hasheretofore been used as the protecting lining material for the pulp.This lining material is used for protecting the dentin from thephosphoric acid etching conducted at the step of filling a material suchas a restorative composite resin. However, if the conventional liningmaterial is used, increase of the thickness of the coating cannot beavoided, and the conventional lining material has no adhesive force to afiller. Accordingly, the conventional lining material can hardly be usedfor filling of a shallow cavity in a tooth. In contrast, when theadhesive coating material of the present invention is dissolved in anorganic solvent and is used as the lining material, the dentin can beprotected from the phosphoric acid etching even though the formedcoating layer is very thin, and furthermore, the material exerts anexcellent function of being bonded to a restorative material.

A zinc phosphate cement which is often used for bonding a metal to thehard tissue involves a risk of damage of the pulp because it contains alarge amount of phosphoric acid. Therefore, the treatment with thiscement inherently includes use of a lining material for protection ofthe dentin. However, in case of the conventional lining materialproviding a thick coating layer, the compressive strength of the coatingmaterial is insufficient and the conventional lining material cannot beused for this purpose. When the adhesive coating material is used as alining material of the above-mentioned type, since the coating layer isvery thin, a high compressive strength is not necessary for the coatinglayer, and moreover, this thin coating layer does not allow permeationof phosphoric acid. Accordingly, the adhesive coating material exertsideal effects.

As the third function of the adhesive coating material, there can bementioned the improvement of a border sealing property.

As the known substance expected to exert this function, there can bementioned, for example, a solution of a resin such as Copalite(tradename) in an organic solvent which is used for filling of amalgam.Indeed, this material provides a thin coating layer, but the materialhas no adhesive force to the dentin or amalgam, and no substantialborder sealing effect can be attained. In contrast, if the adhesivecoating material of the present invention is used as a border sealer, ahigh border sealing effect can be attained. In view of the fact that theadhesive coating material of the present invention can be bonded to thedentin but cannot be bonded to amalgam, it is considered that the abovefunction is due to properties other than the adhesiveness, for example,the close adhesion and hydrophobic property.

When the adhesive coating material of the present invention is used forthe filling operations other than the amalgam filling, for example, therestorative composite resin filling, the cement filling and the rubbercapping, the border sealing effect can be improved.

The adhesive coating material of the present invention can be applied touses other than the above-mentioned uses. For example, when it isintended to remove the material filled in the cavity of a tooth or torestore a wedge-shaped defect on the neck of the tooth, if the adhesivecoating material is coated, it can effectively act as an insulatingmaterial to external stimulant.

The functions of the adhesive coating material of the present inventionas the dental adhesive, the protective lining material for the pulp andthe border sealer have independently been described. Since the adhesivecoating material of the present invention has these functions incombination, if the coating material of the present invention is appliedto the treatment of one case, all of these functions can be exerted atone time. According to the conventional technique, a plurality ofmaterials should be used in combination for the treatment of one case,and hence, the operation becomes complicated, and the functions of therespective materials are degraded of the combined application of thematerials. If this fact is taken into consideration, it will readily beunderstood that the adhesive coating material of the present inventionis very valuable as a dental restorative material.

When the adhesive coating material of the present invention is used as adental restorative material, it is important that the polymer used asone component should have a carboxyl group or carboxylic anhydride groupin addition to the hydrophobic group, and because of the presence of thecarboxyl group or carboxylic acid anhydride group, the function as thedental restorative material is further improved. Namely, the waterresistance is improved so that the above function can sufficiently beexerted even under the severe condition in the oral cavity, that is,100% relative humidity. When the adhesive coating material is used as anadhesive for bonding a composite restorative resin to the dentin, sincethe carboxyl group or carboxylic anhydride group has an affinity withthe dentin and the hydrophobic group has an affinity with the compositerestorative resin, the adhesive force is highly improved over adhesiveforces attainable by conventional adhesives.

The present invention will now be described in detail with reference tothe following Examples that by no means limit the scope of theinvention.

PRODUCTION EXAMPLE 1

A 500 ml-capacity glass separable flask was charged with 200 ml ofcyclohexane, and 5.2 g of styrene, 4.9 g of maleic anhydride and 0.05 gof benzoyl peroxide (hereinafter referred to as "BPO") were added andthe mixture was sufficiently stirred.

Then, the pressure in the vessel was reduced and the atmosphere wasreplaced with nitrogen, and the mixture was heated at 80° C. withstirring for 4 hours to effect polymerization. The reaction mixture wascooled to room temperature and the formed precipitate was recovered byfiltration. The obtained solid was sufficiently washed with 300 ml ofbenzene and dried to obtain 8.7 g of a white polymer. When thecomposition of the formed copolymer was determined by the elementaryanalysis, it was found that the copolymer comprised 48.4 mole % ofstyrene and 51.6 mole % of maleic anhydride.

Then, the product was dissolved in 80 ml of dioxane, and the solutionwas charged into a 500 ml-capacity flask and 100 ml of an aqueoussolution of potassium hydroxide having a concentration of 5% by weightwas added to the solution with sufficient stirring. Reaction was carriedout at room temperature for 10 hours. Then, concentrated hydrochloricacid was added to the reaction mixture to effect neutralization, and anexcessive amount of hydrochloric acid was further added to obtain awhite solid precipitate. The solid was recovered by filtration and itwas washed with water repeatedly until the solid became neutral, and thesolid was dried to obtain 8.0 g of a copolymer. When the product wassubjected to the infrared absorption spectrum analysis, it was foundthat characteristic absorptions attributed to the carbonyl group ofmaleic anhydride at 1850 cm⁻¹ and 1775 cm⁻¹ completely disappeared and acharacteristic absorption attributed to the carbonyl group of maleicacid newly appeared at 1720 cm⁻¹. Thus, it was confirmed that thehydrolysis reaction was advanced substantially quantitatively. Namely,it was confirmed that the obtained white solid was a copolymercomprising 48.4 mole % of styrene and 51.6 mole % of maleic acid.Incidentally, the acid value of the polymer was 370.

PRODUCTION EXAMPLE 2

A solution of 10 g of a commercially available styrene-maleic anhydridecopolymer having a molecular weight of 50,000 (supplied by Monsanto Co.)in 200 ml of dioxane was charged in a 500 ml-capacity flask, and 10 g ofdistilled water was added to the solution with sufficient stirring andthe mixture was heated at 100° C. for 4 hours with stirring. Thesolution was cooled to room temperature and thown into 2 liters ofdistilled water to precipitate a white cotton-like polymer. When thepolymer was washed with water and dried, 9.8 g of a white solid wasobtained. From the results of the elementary analysis and infraredabsorption spectrum analysis, it was confirmed that a styrene-maleicacid copolymer was obtained. Incidentally, the acid value of the polymerwas 367.

PRODUCTION EXAMPLES 3 and 4

In the same manner as described in Production Example 1, twocommercially available styrene-maleic anhydride copolymers (supplied byArco Chemical Co.) differing in their composition as shown in Table 1were hydrolyzed. From the results of the elementary analysis of thestarting copolymers and the results of the infrared absorption spectrumanalysis of the hydrolyzed copolymers, it was confirmed thatstyrene-maleic acid copolymers having compositions shown in Table 1 wereobtained. The molecular weights of the copolymers were 1,700 and 1,900,and the acid values of the copolymers were 251 and 184.

                  TABLE 1                                                         ______________________________________                                               Tradename of Commer-                                                                        Composition of Styrene-                                         cially Available                                                                            Maleic Acid Copolymer                                    Production                                                                             Maleic Anhydride-                                                                             styrene   maleic acid                                Example No.                                                                            Styrene Copolymer                                                                             (mole %)  (mole %)                                   ______________________________________                                        3        SMA 2000        66.7      33.3                                       4        SMA 3000        75.1      24.9                                       ______________________________________                                    

PRODUCTION EXAMPLE 5

A pressure glass vessel having an inner capacity of 300 ml was chargedwith 50 ml of benzene containing 35 g of maleic anhydride and 90 mg ofazobisisobutyronitrile (hereinafter referred to as "AIBN"), and theinner atmosphere was replaced by nitrogen under reduced pressure whilecooling in a dry ice-methanol bath. Then, 12 g of propylene wasintroduced into the reaction vessel by distillation through aliquefaction meter, and the mixture was stirred at 60° C. for 36 hoursto effect copolymerization. After the termination of the polymerization,the content was thrown into a large amount of anhydrous ether toprecipitate the formed copolymer. The polymer was sufficiently washed bydecantation and promptly dried in a reduced pressure dryer. The yieldwas 60%. From the results of the elementary analysis, it was found thatthe copolymer comprised 55.6 mole % of maleic anhydride and 44.4 mole %of propylene.

Then, the product was hydrolyzed in the same manner as described inProduction Example 1 to obtain 24.2 g of a propylene-maleic acidcopolymer. From the results of the infrared absorption spectrumanalysis, it was confirmed that the maleic anhydride group in thestarting copolymer was converted to maleic acid substantiallyquantitatively. Incidentally, the acid value of the polymer was 508.

PRODUCTION EXAMPLE 6

A pressure glass vessel having an inner capacity of 300 ml was chargedwith 50 ml of benzene containing 35.7 g of maleic anhydride and 90 mg ofAIBN, and 12.5 g of isobutene was introduced into the reaction vessel bydistillation through a liquefaction meter and copolymerization wascarried out at 60° C. for 15 minutes. After the termination of thepolymerization, the content was thrown into a large amount of anhydrousether to precipitate the formed copolymer, and the supernatant wasdiscarded by decantation and the residue was sufficiently washed withanhydrous ether and then dried under reduced pressure. The yield was43.3%. From the results of the elementary analysis, it was found thatthe product was a copolymer comprising 47.1 mole % of isobutene and 52.9mole % of maleic anhydride.

In the same manner as described in Production Example 1, the product washydrolyzed to obtain 20.5 g of an isobutene-maleic acid copolymer. Fromthe results of the infrared absorption spectrum analysis of thiscopolymer, it was confirmed that the maleic anhydride group in thestarting copolymer was converted to maleic acid substantiallyquantitatively. Incidentally, the acid value of this copolymer was 470.

PRODUCTION EXAMPLE 7

A 500 ml-capacity glass separable flask was charged with 200 ml ofbenzene, and 5.3 g of n-butylvinyl ether, 4.9 g of maleic anhydride and0.05 g of AIBN were added and the mixture was sufficiently stirred.

Then, the pressure in the vessel was reduced and the inner atmospherewas replaced by nitrogen, and heat polymerization was carried out at 60°C. for 6 hours and the formed precipitate was recovered by filtration.From the results of the elementary analysis, it was found that theformed copolymer comprised 49.8 mole % of n-butylvinyl ether and 50.2mole % of maleic anhydride. Then, the product was dissolved in 200 ml ofdioxane and the solution was charged in a 500 ml-capacity flask, and 10g of distilled water was added under sufficient stirring and the mixturewas heated and stirred at 60° C. for 2 hours. The obtained polymersolution was solidified by dry ice-methanol and then freeze-dried toobtain 10.1 g of a white solid. From the results of the infraredabsorption spectrum analysis of the product, it was confirmed that themajority of the maleic anhydride group in the starting copolymer wasconverted to a maleic acid group. Incidentally, the acid value of thepolymer was 375.

PRODUCTION EXAMPLE 8

A commercially available n-octadecylvinyl ethermaleic anhydridecopolymer (supplied by Polysciences, Inc.) was hydrolyzed in the samemanner as described in Production Example 2. From the results of theelementary nalysis of the starting copolymer and the results of theinfrared absorption spectrum analysis of the hydrolyzed copolymer, itwas confirmed that the product was an n-octadecylvinyl ether-maleic acidcopolymer having an acid value of 196.

PRODUCTION EXAMPLE 9

In 200 g of dioxane were dissolved 30 g of itaconic acid and 20 g ofstyrene, and BPO was added to the solution in an amount of 0.1% based onthe monomers and polymerization was carried out at 10° C. for 5 hours.The reaction mixture was thrown in 1 lter of hexane, and the precipitatewas recovered by filtration, dried and washed with distilled water toremove unreacted itaconic acid. The yield was 4.2%. From the results ofthe elementary analysis, it was found that the product was a copolymercomprising 49.0 mole % of itaconic acid and 51.0 mole % of styrene. Theacid value of the polymer was 340.

PRODUCTION EXAMPLE 10

Styrene was copolymerized with diethyl fumarate at 60° C. for 20 hoursby using AIBN as the initiator. From the results of the elementaryanalysis of the formed polymer, it was found that the formed polymer wasa copolymer comprising 56.5 mole % of styrene and 43.5 mole % of diethylfumarate. Then, 0.5 g of the polymer was charged in an Erlenmeyer flaskhaving an inner capacity of 100 ml, and 30 ml of concentrated sulfuricacid was added and the mixture was allowed to stand still. In 2 days,the polymer was completely dissolved and a yellow solution was obtained.When the solution was poured into a large amount of ice water, astyrene-fumaric acid copolymer was precipitated. The precipitate wasrecovered by filtration, washed sufficiently with water repeatedly anddried to obtain 0.45 g of a solid. The acid value of the polymer was 93.

PRODUCTION EXAMPLE 11

A commercially available vinyl acetate-maleic anhydride copolymer(supplied by Polysciences, Inc.) was hydrolyzed in the same manner asdescribed in Production Example 7. From the results of the elementaryanalysis of the starting copolymer and the results of the infraredabsorption spectrum analysis of the hydrolyzed copolymer, it was foundthat the product was a vinyl acetate-maleic acid copolymer. The acidvalue of the polymer was 399.

PRODUCTION EXAMPLE 12

p-Chlorostyrene was copolymerized with maleic anhydride by using BPO asthe initiator under the same conditions as adopted in ProductionExample 1. From the results of the elementary analysis of the obtainedcopolymer, it was found that the obtained copolymer comprised 47.9 mole% of p-chlorostyrene and 52.1 mole % of maleic anhydride. The productwas hydrolyzed in the same manner as described in Production Example 7.From the results of the elementary analysis of the formed polymer andthe results of the infrared absorption spectrum analysis of thehydrolyzed polymer, it was confirmed that the product was a vinylacetate-maleic acid copolymer. The acid value of this polymer was 318.

PRODUCTION EXAMPLE 13

p-Chloromethylstyrene was copolymerized with maleic anhydride by usingBPO as the initiator under the same conditions as adopted in ProductionExample 1. From the results of the elementary analysis of the obtainedcopolymer, it was found that the formed copolymer comprised 48.9 mole %of p-chloromethylstyrene and 51.1 mole % of maleic anhydride. Theproduct was hydrolyzed in the same manner as described in ProductionExample 7. From the results of the elementary analysis of the formedcopolymer and the results of the infrared absorption spectrum analysisof the hydrolyzed copolymer, it was confirmed that the product was ap-chloromethylstyrenemaleic acid copolymer. The acid value of thispolymer was 301.

EXAMPLE 1

(i) Liquids (I) and (II) shown in Table 2 were prepared by using thecopolymer obtained in Production Example 1 and an organic titanate shownin Table 2. In Table 2, the amount used of the copolymer (parts byweight per 90 parts by weight of ethanol) and the amount used of theorganic titanate (parts by weight per 100 parts by weight of ethanol)are shown. The adhesive strength of an adhesive coating material formedfrom these liquids (I) and (II) was determined according to thefollowing procedures.

Pastes (A) and (B) were prepared according to the following recipes.

    ______________________________________                                        Paste (A):                                                                    Bisphenol-A-diglycidyl methacrylate                                                                 11.0   parts by weight                                  Triethylene glycol dimethacrylate                                                                   10.5   parts by weight                                  (hereinafter referred to as                                                   "TEGDMA")                                                                     DMPT                  0.5    part by weight                                   Silane-treated quartz powder                                                                        78.0   parts by weight                                  (having particle size smaller                                                 than 80 microns)                                                              Paste (B):                                                                    Bisphenol-A-diglycidyl methacry-                                                                    11.0   parts by weight                                  late                                                                          TEDMA                 10.5   parts by weight                                  BPO                   1.0    part by weight                                   Silane-treated quartz powder                                                                        78.0   parts by weight                                  (having particle size smaller                                                 than 80 microns)                                                              ______________________________________                                    

The lip side surface of a freshly extracted bovine tooth was polished byemery paper (#320) to expose a smooth dentin, and nitrogen gas was blownto dry the surface. Then, a plate-like wax having a through hole havinga diameter of 4 mm was attached to the dried surface by using adouble-coated tape. Then, the adhesive liquids (I) and (II) were mixedat a ratio of 1:1 and the mixture was coated on the dentin surfacesurrounded by the plate-like wax, and nitrogen gas was blown to sweepoff the excessive adhesive. Then, the pastes (A) and (B) were mixed at aratio of 1:1 and the mixture was filled onto the adhesive coating. Afterstanding for 1 hour, the plate-like wax was removed, and the treatedtooth was dipped in water maintained at 37° C. for 24 hours and thetensile strength was measured at a pulling speed of 10 mm/min by usingTensilon supplied by Toyo-Baldwin. The obtained results are shown inTable 2.

(ii) In order to confirm that the coating layer of the adhesive coatingmaterial of the present invention has an insulating effect to an aqueoussolution of phosphoric acid, the following test was carried out.

A membrane filter having a pore size of 3 microns was dipped indistilled water for 1 hour, and the membrane filter was taken out andwas dried by blowing nitrogen gas to the surface of the membrane filter.Then, the dried surface of the membrane filter was coated with acommercially available insulating material (lining material) (Copaliteor Dycal, each being a tradename) or the adhesive coating material usedin Example 1. Then, nitrogen gas was blown to the surface again toremove the solvent. One drop of a 37% aqueous solution oforthophosphoric acid was applied to the surface of the insulatingcoating, and the coated membrane filter was allowed to stand still.

In order to detect phosphoric acid permeating through the insulatinglayer, a pH test paper was placed below the membrane filter and theinsulating property was evaluated based on the permeation time, namelythe time at which the color of the pH test paper was changed.

When the insulating material was not used, the permeation time was 15seconds. When Copalite (tradename) was used, the permeation time was 1minute and 10 seconds, and when Dycal (tradename) was used, thepermeation time was more than 10 minutes. In contrast, when adhesivecoating materials of the present invention (Runs Nos. 1 through 5 inTable 2) were used, the permeation time of the aqueous solution ofphosphoric acid was more than 10 minutes in each case.

                  TABLE 2                                                         ______________________________________                                                                            Adhesive                                       Liquid (I)    Liquid (II)      Strength                                  Run  Polymer (parts                                                                              Organic Titanate Com-                                                                          (kg/cm.sup.2)                             No.  by weight)    pound (parts by weight)                                                                        to Dentin                                 ______________________________________                                        1    copolymer of Pro-                                                                           tetraisopropyl   18.0                                           duction Example                                                                             titanate (2)                                                    1 (10)                                                                   2    copolymer of Pro-                                                                           tetrabutyl       37.5                                           duction Example                                                                             titanate (2)                                                    1 (10)                                                                   3    copolymer of Pro-                                                                           tetrakis(2-ethylhexyl)                                                                         14.5                                           duction Example                                                                             titanate (2)                                                    1 (10)                                                                   4    copolymer of Pro-                                                                           dimer of tetrabutyl                                                                            32.0                                           duction Example                                                                             titanate (2)                                                    1 (10)                                                                   5    copolymer of Pro-                                                                           tetramer of tetrabutyl                                                                         27.0                                           duction Example                                                                             titanate (2)                                                    1 (10)                                                                   ______________________________________                                    

EXAMPLE 2

The procedures of Example 1 (Run No. 1 in Table 2) were repeated in thesame manner except that a stabilizer shown in Table 6 was added to theorganic titanate used in Example 1 (Run No. 1 in Table 2). The obtainedresults are shown in Table 6. The storage stability of the liquid (II)was evaluated by checking the transparency and the change of theviscosity in the solution. Incidentally, it was found that when both theliquids (I) and (II) were mixed, gelation or precipitation was causedwithin several days in each run.

                                      TABLE 3                                     __________________________________________________________________________               Liquid (II)       Adhesive                                            Liquid (I)                                                                            Organic Titanate                                                                       Stabilizer                                                                             Strength                                         Run                                                                              Polymer (parts                                                                        Compound (parts                                                                        (parts by                                                                              (kg/cm.sup.2)                                                                      Storage                                     No.                                                                              by weight)                                                                            by weight)                                                                             weight)  to Dentin                                                                          Stability                                   __________________________________________________________________________    1  copolymer of                                                                          tetra-n-butyl                                                                          lactic acid (1)                                                                        36.9 4 months                                       Production                                                                            titanate (2)                                                          Example 1 (10)                                                             2  copolymer of                                                                          tetra-n-butyl                                                                          α-hydroxy-n-                                                                     37.3 1 year                                         Production                                                                            titanate (2)                                                                           butyric acid                                                 Example 1 (10)   (1)                                                       3  copolymer of                                                                          tetra-n-butyl                                                                          mandelic acid                                                                          35.8 6 months                                       Production                                                                            titanate (2)                                                                           (1)                                                          Example 1 (10)                                                             4  copolymer of                                                                          tetra-n-butyl                                                                          β-hydroxyethyl                                                                    36.1 6 months                                       Production                                                                            titanate (2)                                                                           methacrylate (1)                                             Example 1 (10)                                                             5  copolymer of                                                                          tetra-n-butyl                                                                          glycerin dime-                                                                         38.2 6 months                                       Production                                                                            titanate (2)                                                                           thacrylate (1)                                               Example 1 (10)                                                             6  copolymer of                                                                          tetra-n-butyl                                                                          guaiacol (1)                                                                           30.9 6 months                                       Production                                                                            titanate (2)                                                          Example 1 (10)                                                             7  copolymer of                                                                          tetra-n-butyl                                                                          eugenol (1)                                                                            36.3 6 months                                       Production                                                                            titanate (2)                                                          Example 1 (10)                                                             8  copolymer of                                                                          tetra-n-butyl                                                                          proline (1)                                                                            29.8 8 months                                       Production                                                                            titanate (2)                                                          Example 1 (10)                                                             9  copolymer of                                                                          tetra-n-butyl                                                                          4-methylpro-                                                                           29.5 10 months                                      Production                                                                            titanate (2)                                                                           line (1)                                                     Example 1 (10)                                                             10 copolymer of                                                                          tetra-n-butyl                                                                          β-butyrolac-                                                                      32.8 1 month                                        Production                                                                            titanate (2)                                                                           tone (1)                                                     Example 1 (10)                                                             11 copolymer of                                                                          tetra-n-butyl                                                                          γ-butyrolac-                                                                     33.5 1 month                                        Production                                                                            titanate (2)                                                                           tone (1)                                                     Example 1 (10)                                                             __________________________________________________________________________

EXAMPLE 3

The liquids (I) and (II) were prepared in the same manner as in Example1 (Run No. 2 in Table 2) except that the organic titanate used inExample 1 (Run No. 2 in Table 2) and a stabilizer shown in Table 4 wereused. Then, the liquids (I) and (II) were mixed. Each of the resultingsolutions having a composition shown in Table 4 was kept transparent andno change of the viscosity was caused for more than 1 , week. Afterpassage of 1 week from the time of mixing the liquids (I) and (II), thebonding test was carried out in the same manner as in Example 2. Thestorage stability in the one-pack state was subsequently observed. Theobtained results are shown in Table 4.

The following test was carried out so as to examine the border sealingproperty of each composition.

A cavity having a diameter of 3 mm and a depth of 2 mm was formed on thelip side surface of an extracted human tooth. Adhesive coating materialsof Example 3 (Runs Nos. 1 to 6 in Table 4) and Copalite as theconventional material were used as the sample. The sample was thinlycoated on the cavity, and then, a cement or amalgam was filled in thecavity. After passage of 1 hour, the tooth was stored in watermaintained at 37° C., and after passage of 1 day, the tooth was dippedin an aqueous solution of Fuchsine maintained at 4° C. for 1 minute andthen in an aqueous solution of Fuchsine maintained at 60° C. for 1minute and this operation was repeated 60 times, whereby the percolationtest was carried out. The border sealing effect was evaluated by cuttingthe tooth at the center and checking whether the dye (Fuchsine) hadintruded between the cavity and the filler. In each run, five specimenswere used so as to confirm the reproducibility. When the amalgam orcement was directly filled without using any material, or when Copalitewas coated and the amalgam or cement was then filled, intrusion of thedye was observed in each specimen. In contrast, in case of each of theadhesive coating materials of Example 3 (Runs Nos. 1 through 6 in Table4), intrusion of the dye was not observed and good results wereobtained.

                                      TABLE 4                                     __________________________________________________________________________                Liquid (II)       Adhesive                                           Liquid (I)                                                                             Organic Titanate  Strength                                        Run                                                                              Polymer (parts                                                                         Compound (parts                                                                        Stabilizer (parts                                                                      (kg/cm.sup.2)                                                                      Storage                                    No.                                                                              by weight)                                                                             by weight)                                                                             by weight)                                                                             to Dentin                                                                          Stability                                  __________________________________________________________________________    1  copolymer of Pro-                                                                      tetra-n-butyl                                                                          o-methoxybenzoic                                                                       37.5 more than                                     duction Example                                                                        titanate (2)                                                                           acid (1)      1 year                                        1 (10)                                                                     2  copolymer of Pro-                                                                      tetra-n-butyl                                                                          o-ethoxybenzoic                                                                        39.2 more than                                     duction Example                                                                        titanate (2)                                                                           acid (1)      1 year                                        1 (10)                                                                     3  copolymer of Pro-                                                                      tetra-n-butyl                                                                          o-propoxybenzoic                                                                       35.2 more than                                     duction Example                                                                        titanate (2)                                                                           acid (1)      1 year                                        1 (10)                                                                     4  copolymer of Pro-                                                                      tetra-n-butyl                                                                          hydroxyacrylic                                                                         35.5 more than                                     duction Example                                                                        titanate (2)                                                                           acid (1)      1 year                                        1 (10)                                                                     5  copolymer of Pro-                                                                      tetra-n-butyl                                                                          β-hydroxybutyric                                                                  32.8 more than                                     duction Example                                                                        titanate (2)                                                                           acid (1)      1 year                                        1 (10)                                                                     6  copolymer of Pro-                                                                      tetra-n-butyl                                                                          β-hydroxyisovale-                                                                 33.5 more than                                     duction Example                                                                        titanate (2)                                                                           ric acid (1)  1 year                                        1 (10)                                                                     __________________________________________________________________________

EXAMPLE 4

The procedures of Example 3 (Run No. 2 in Table 4) were repeated in thesame manner except that a polymer shown in Table 5 was used instead ofthe polymer used in Example 3 (Run No. 2 in Table 4). The obtainedresults are shown in Table 5.

                                      TABLE 5                                     __________________________________________________________________________              Liquid (II)                                                                         Organic Titanate                                                                       Stabilizer                                           Run                                                                              Liquid (I)   Compound (parts                                                                        (parts by                                                                             Adhesive Strength                            No.                                                                              Polymer (parts by weight)                                                                  by weight)                                                                             weight) (Kg/cm.sup.2) to Dentin                      __________________________________________________________________________    1  copolymer of Production                                                                    tetrabutyl tita-                                                                       o-ethoxybenzoic                                                                       39.2                                            Example 1 (10)                                                                             nate (2) acid (1)                                             2  copolymer of Production                                                                    tetrabutyl tita-                                                                       o-ethoxybenzoic                                                                       38.1                                            Example 1 (6)                                                                              nate (1.5)                                                                             acid (1)                                             3  copolymer of Production                                                                    tetrabutyl tita-                                                                       o-ethoxybenzoic                                                                       36.2                                            Example 1 (12)                                                                             nate (3) acid (1)                                             4  copolymer of Production                                                                    tetrabutyl tita-                                                                       o-ethoxybenzoic                                                                       36.6                                            Example 2 (8)                                                                              nate (2) acid (1)                                             5  copolymer of Production                                                                    tetrabutyl tita-                                                                       o-ethoxybenzoic                                                                       24.1                                            Example 3 (15)                                                                             nate (2) acid (1)                                             6  copolymer of Production                                                                    tetrabutyl tita-                                                                       o-ethoxybenzoic                                                                       19.1                                            Example 4 (18)                                                                             nate (2) acid (1)                                             7  copolymer of Production                                                                    tetrabutyl tita-                                                                       o-ethoxybenzoic                                                                       27.1                                            Example 5 (10)                                                                             nate (2) acid (1)                                             8  copolymer of Production                                                                    tetrabutyl tita-                                                                       o-ethoxybenzoic                                                                       29.5                                            Example 6 (10)                                                                             nate (2) acid (1)                                             9  copolymer of Production                                                                    tetrabutyl tita-                                                                       o-ethoxybenzoic                                                                       19.9                                            Example 7 (10)                                                                             nate (2) acid (1)                                             10 copolymer of Production                                                                    tetrabutyl tita-                                                                       o-ethoxybenzoic                                                                       18.1                                            Example 8 (10)                                                                             nate (2) acid (1)                                             11 copolymer of Production                                                                    tetrabutyl tita-                                                                       o-ethoxybenzoic                                                                       29.1                                            Example 9 (10)                                                                             nate (2) acid (1)                                             12 copolymer of Production                                                                    tetrabutyl tita-                                                                       o-ethoxybenzoic                                                                       15.3                                            Example 10 (10)                                                                            nate (2) acid (1)                                             13 copolymer of Production                                                                    tetrabutyl tita-                                                                       o-ethoxybenzoic                                                                       20.0                                            Example 11 (10)                                                                            nate (2) acid (1)                                             14 copolymer of Production                                                                    tetrabutyl tita-                                                                       o-ethoxybenzoic                                                                       34.1                                            Example 12 (10)                                                                            nate (2) acid (1)                                             15 copolymer of Production                                                                    tetrabutyl tita-                                                                       o-ethoxybenzoic                                                                       35.6                                            Example 13 (10)                                                                            nate (2) acid (1)                                             __________________________________________________________________________

EXAMPLE 5

By using liquids (I) and (II) for the first treatment, shown in Table 6,an untreated dentin of a bovine tooth was subjected to the coatingtreatment in the same manner as described in Example 1. Then, the coatedsurface was further coated with a liquid mixture of liquids (I') and(II') for the second treatment, shown in Table 6. Namely, liquid (I')comprising 10 parts by weight of a commercially available styrene/maleicanhydride copolymer (SMA 1000), 90 parts by weight of 2-hydroxyethylmethacrylate and 1 part by weight of BPO was mixed with liquid (II')comprising 1.5 parts by weight of DEPT, 3.0 parts by weight of sodiump-toluene-sulfinate and 100 parts by weight of ethanol at a ratio of1:1, and the resulting liquid mixture was coated on the coated surfaceof the tooth. The adhesive test was carried out in the same manner asdescribed in Example 1. The obtained results are shown in Table 6.

                                      TABLE 6                                     __________________________________________________________________________             First Treatment                                                               Liquid (I) Liquid (II)                                               Run      Polymer (parts                                                                           Organic Titanate                                                                         Stabilizer (parts                              No.      by weight) (parts by weight)                                                                        by weight)                                     __________________________________________________________________________    1        copolymer of                                                                             tetra-n-butyl                                                                            lactic acid (1)                                         Production titanate (2)                                                       Example 1 (10)                                                       2        copolymer of                                                                             tetra-n-butyl                                                                            2-hydroxyethyl                                          Production titanate (2)                                                                             methacrylate (1)                                        Example 1 (10)                                                       3        copolymer of                                                                             tetra-n-butyl                                                                            eugenol (1)                                             Production titanate (2)                                                       Example 1 (10)                                                       4        copolymer of                                                                             tetra-n-butyl                                                                            proline (1)                                             Production titanate (2)                                                       Example 1 (10)                                                       5        copolymer of                                                                             tetra-n-butyl                                                                            o-ethoxybenzoic                                         Production titanate (2)                                                                             acid (1)                                                Example 1 (10)                                                       6        copolymer of                                                                             tetra-n-butyl                                                                            β-hydroxybutyric                                   Production titanate (2)                                                                             acid                                                    Example 1 (10)                                                       __________________________________________________________________________    Second Treatment                                                              Liquid (I')             Liquid (II')                                                     Polymerizable                                                                         Peroxide                                                                           Amine       Adhesive                                             Vinyl Com-                                                                            Catalyst                                                                           Catalyst                                                                             Promotor                                                                           Strength                                  Run                                                                              Polymer (parts                                                                        pound (parts                                                                          (parts by                                                                          (parts by                                                                            (parts by                                                                          (Kg/cm.sup.2) to                          No.                                                                              by weight)                                                                            by weight)                                                                            weight)                                                                            weight)                                                                              weight)                                                                            Dentin                                    __________________________________________________________________________    1  SMA-1000 (10)                                                                         2-hydroxyethyl                                                                        BPO (1)                                                                            DEPT (1.5)                                                                           sodium p-                                                                          45.6                                                 methacrylate        toluene-                                                  (30), triethy-      sulfinate                                                 lene glycol         (3.0)                                                     dimethacrylate                                                                (60)                                                               2  SMA-1000 (10)                                                                         2-hydroxyethyl                                                                        BPO (1)                                                                            DEPT (1.5)                                                                           sodium p-                                                                          46.0                                                 methacrylate        toluene-                                                  (30), triethy-      sulfinate                                                 lene glycol         (3.0)                                                     dimethacrylate                                                                (60)                                                               3  SMA-1000 (10)                                                                         2-hydroxyethyl                                                                        BPO (1)                                                                            DEPT (1.5)                                                                           sodium p-                                                                          45.0                                                 methacrylate        toluene-                                                  (30), triethy-      sulfinate                                                 lene glycol         (3.0)                                                     dimethacrylate                                                                (60)                                                               4  SMA-1000 (10)                                                                         2-hydroxyethyl                                                                        BPO (1)                                                                            DEPT (1.5)                                                                           sodium p-                                                                          38.5                                                 methacrylate        toluene-                                                  (30), triethy-      sulfinate                                                 lene glycol         (3.0)                                                     dimethacrylate                                                                (60)                                                               5  SMA-1000 (10)                                                                         2-hydroxyethyl                                                                        BPO (1)                                                                            DEPT (1.5)                                                                           sodium p-                                                                          48.9                                                 methacrylate        toluene-                                                  (30), triethy-      sulfinate                                                 lene glycol         (3.0)                                                     dimethacrylate                                                                (60)                                                               6  SMA-1000 (10)                                                                         2-hydroxyethyl                                                                        BPO (1)                                                                            DEPT (1.5)                                                                           sodium p-                                                                          44.1                                                 methacrylate        toluene-                                                  (30), triethy-      sulfinate                                                 lene glycol         (3.0)                                                     dimethacrylate                                                                (60)                                                               __________________________________________________________________________

We claim:
 1. An adhesive coating material for a hard tissue, whichcomprises (1) a polymer having an acid value of 30 to 700 and repeatingunits of the polymer including a hydrophobic group and repeating unitsof the polymer including two carboxyl (--COOH) groups bonded to thepolymer, said carboxyl groups being bonded to adjacent carbon atoms, and(2) an organic titanate compound.
 2. An adhesive coating material as setforth in claim 1, wherein the hydrophobic group is present in themolecule of the polymer in an amount of 0.7 to 9.0 moles per mole of thetwo carboxyl groups.
 3. An adhesive coating material as set forth inclaim 1, wherein the molecular weight of the polymer is 1,000 to100,000.
 4. An adhesive coating material as set forth in claim 1,wherein the average hydrophobic group is at least one member selectedfrom the group consisting of aryl groups, alkyl groups, alkoxy groupsand acyloxy groups.
 5. An adhesive coating material as set forth inclaim 1, wherein the polymer is a copolymer comprising a vinyl monomerhaving a hydrophobic group and a vinyl monomer having two carboxylgroups bonded to adjacent carbon atoms.
 6. An adhesive coating materialas set forth in claim 5, wherein the vinyl monomer having a hydrophobicgroup is a monomer represented by the following general formula:##STR8## wherein R¹ stands for a hydrogen atom or an alkyl group, and R²stands for an aryl group, an alkyl group, an alkoxy group or an acyloxygroup.
 7. An adhesive coating material as set forth in claim 5, whereinthe vinyl monomer having two carboxyl groups bonded to adjacent carbonatoms is a member selected from the group consisting of maleic acid,fumaric acid, and itaconic acid.
 8. An adhesive coating material as setforth in claim 1, wherein the polymer comprises (A) at least onerepeating unit represented by the following formula: ##STR9## wherein R¹stands for a hydrogen atom or an alkyl group, and R² stands for an arylgroup, an alkyl group, an alkoxy group or an acyloxy group and (B) atleast one repeating unit represented by the following formula: ##STR10##wherein R³ stands for a hydrogen atom or a carboxymethyl group, n and mare numbers of zero or 1, with the proviso that when n is zero, m is 1and R³ is a hydrogen atom and when n is 1, m is zero and R³ is acarboxymethyl group.
 9. An adhesive coating material as set forth inclaim 1, wherein the organic titanate compound is a tetraalkyl titanate.10. An adhesive coating material as set forth in claim 1, wherein theorganic titanate compound is a titanate represented by the followingformula: ##STR11## wherein R⁴ stands for an alkyl group and p is anumber of from 0 to
 20. 11. An adhesive coating material as set forth inclaim 1, wherein in the mixture of the polymer and the organic titanatecompound, the organic titanate compound is contained in an amount of0.02 to 2 moles per mole of the two carboxyl groups of the polymer. 12.An adhesive coating material for a hard tissue, which comprises (1) apolymer having an acid value of 30 to 700 and repeating units of thepolymer including a hydrophobic group and repeating units of the polymerincluding two carboxyl (--COOH) groups bonded to the polymer, saidcarboxyl groups being bonded to adjacent carbon atoms, (2) an organictitanate compound and (3) a stabilizer for the organic titanatecompound.
 13. An adhesive coating material as set forth in claim 12,wherein the stabilizer for the organic titanate compound is ano-alkoxybenzoic acid or β-hydroxycarboxylic acid.
 14. An adhesivecoating material as set forth in claim 12, wherein the stabilizer forthe organic titanate compound is at least one member selected from thegroup consisting of α-hydroxycarboxylic acids, β-hydroxyalkyl acrylates,β-hydroxyalkyl methacrylates, catechol derivatives, proline derivativesand cyclic ethers.